Method of manufacturing disc brake caliper housings

ABSTRACT

A DISC BRAKE CALIPER HOUSING IS MADE FROM AN EXTRUDE PIPE BY CUTTING THE PIPE INTO SEGMENTS AND TRANSVERSELY NOTCHING EACH SEGMENT TO PROVIDE SPACE FOR RECEIVING THE DISC TO BE BRAKED AND FOR MOUNTING THE BRAKE PADS. THE PIPE CROSS SECTION PATTERN PROVIDES SUITABLE   OPENINGS FOR MOUNTING WHEEL CYLINDER ASSEMBLIES, FOR COOLING, AND FOR WEIGHT REDUCTION.

Dec. 14, 1971 H. SHAKESPEAR METHOD OF MANUFACTURING DISC BRAKE CALIPER HOUSINGS Original Filed Oct. 1, 1968 2 Sheets-Sheet 1 INVENTOR. /%z'aczb Shah's BY pear W flw/ 14 7' TORNE Y Dec. 14, 1971 H. SHAKESPEAR 3,626,580

METHOD OF MANUFACTURING DISC BRAKE CALIPER HOUSINGS Original Filed on. 1. 1 968 2 Sheets-Sheet z f 52 7 EXTRUSION DIE \ JQ/C/QC/C/C/v' 7 l 1 f y- 4% 6 86 V 9 K V 8 QmJ y Y v I lNV/ZN'I'UR.

United States Patent 3,626,580 METHOD OF MANUFACTURING DISC BRAKE CALIPER HOUSINGS Horacio Shakespear, Troy, Mich., assignor to General Motors Corporation, Detroit, Mich.

Original application Oct. 1, 1968, Ser. No. 764,261, now Patent No. 3,556,265, dated Jan. 19, 1971. Divided and this application Sept. 19, 1969, Ser. No. 859,383

Int. Cl. B23p 17/00 US. Cl. 29-412 1 Claim ABSTRACT OF THE DISCLOSURE A disc brake caliper housing is made from an extruded pipe by cutting the pipe into segments and transversely notching each segment to provide space for receiving the disc to be braked and for mounting the brake pads. The pipe cross section pattern provides suitable openings for mounting wheel cylinder assemblies, for cooling, and for weight reduction.

This is a division of Ser. No. 764,261, now Pat. No. 3,556,265, filed Oct. 1, 1968. The invention relates to a method of making a disc brake caliper housing which has opposed side sections and a bridging section joining the side sections, the housing sections all having transversely aligned cross section areas formed to a common cross section pattern. The pattern is obtained by extruding a pipe having suitable longitudinal passages, and forming the housing from a segment of the pipe.

Caliper housings have commonly been manufactured in several sections which are cast, machined and fastened together. Cast housings provide the requisite strength to resist spreading as the brake shoes are pressed against the opposed surfaces of the disc to be braked, and also to take torque reaction from the disc to the caliper support bracket. When caliper housings are utilized which are not required to take torque reaction, different strength considerations may be given in the design of the housings. By manufacturing housings in accordance with the invention, significant cost reductions may be obtained without sacrificing design features. A minimum amount of machining of the housing is required, resulting in reduced tooling and labor charges as well as a reduction in waste material. A caliper housing embodying the invention is arranged to extend over a portion of a disc to be braked so that the caliper side sections provide suitable mountings for friction pads and the caliper bridging section joining the side sections is adequate to resist the spreading tendency of the side sections when the brakes are applied. Replacement of worn friction pads is accomplished easily without having to break the fluid integrity of the brake system.

In the drawings:

FIG. 1 is a cross section view of a disc brake assembly associated with a vehicle wheel to be braked, and utilizing a caliper housing embodying the invention;

FIG. 2 is a view of the caliper housing and mounting arrangement of the brake assembly of FIG. 1 taken in the direction of arrows 22 of that figure;

FIG. 3 is a perspective view of the caliper housing forming a part of the brake assembly of FIG. 1;

FIG. 4 is a diagrammatic representation of the step of extruding a pipe from which caliper housing units are to be formed;

FIG. 5 is a diagrammatic representation of the step of separating the extruded pipe of FIG. 4 into segments, with each segment being a pipe unit which is to become a caliper housing;

FIG. 6 shows one pipe unit having a notch formed 3,626,588 Patented Dec. 14, 1971 transversely through a portion thereof as another step in the manufacture of the caliper housing;

FIG. 7 is an end view taken in the direction of arrows 7-7 in FIG. 4 of the extruded pipe showing the cross section pattern of the pipe; and

FIGS. 8 and 9 show modified end views of pipes similar to the pipe of FIG. 7 and which may be utilized in the manufacture of disc brake caliper housings embodying the invention.

The brake assembly 10 shown in FIG. 1 includes a mounting bracket 12 attached to or formed as a part of the axle 14 on which the wheel 16 is rotatably mounted by means of the wheel hub 18 and suitable bearings 20 and 22. The brake disc 24 is secured to the hub 18 by means of bolts 26 so that the disc rotates with the wheel. The caliper assembly 28 includes the caliper housing 30, brake friction pads 32 and 34 with their respective backing plates 36 and 38, and a wheel cylinder assembly 40 having a cylinder 42 containing a piston 44 movable therein to cause the friction pads to engage the opposed friction surfaces of the disc 24. In the particular brake illustrated, the caliper housing is movable transversely of the disc when the wheel cylinder assembly is pressurized so as to bring both friction pads into braking engagement with the disc. If desired, a wheel cylinder assembly ,could be provided on each side of the disc.

The caliper housing 30 has side sections 46 and 48 joined by a bridging section 50 which passes over the outer periphery of disc 24. In the particular housing illustrated, the notch 52 provided transversely through a portion of the housing permits reception of the disc 24 between the housing side sections 46 and 48 and also provides for suitable mounting of the friction pads with their backing plates 36 and 38.

In the brake assembly illustrated, the caliper housing is supported on the friction pad backing plates, as can be better seen in FIG. 2. In this particular arrangement, the mounting bracket 12 has two arms 54 and 5.6 which extend parallel to one disc braking surface until they pass beyond the disc outer periphery. They then extend over the disc outer periphery and inwardly parallel to the other disc friction braking surface. The adjacent edges of the arms 54 and 56, as seen in FIG. 2, are recessed at 58 and 60 as to receive the ends 62 and 64 of the friction pad backing plates. In this construction, the recesses 58 and 60 are provided as notches, and the backing plate ends 62 and 64 are formed with complementary surfaces so that when the backing plates are in position they cannot be moved radially inwardly or outwardly relative to the disc for any appreciable distance. The radially outer edges 66 and 67 of the backing plates rest at the bottom of the caliper housing notch 52 so that the caliper housing is supported on the backing plates 36 and 38 both radially and circumferentially relative to the disc 24. Tension springs 68 and 70 extend across the top of the bridging section 50 of the caliper housing and have their ends fastened by suitable means, such as bolts 72 and 74, to the mounting bracket arms 54 and 56. In this manner suificient radially inward force is maintained against the caliper housing 30 to keep it in position on the backing plates 36 and 38. This also permits quick removal of the caliper housing by releasing one end of each spring after the wheel 16 is removed and removing the caliper housing bv lifting it radially outward. This can be done without disturbing the hydraulic integrity of the brake system. After removal of the caliper housing the friction pad assemblies may be easily re placed. The housing is then again placed over the backing plates and secured in place by fastening the ends of springs 68 and 70.

With this disc brake arrangement the caliper housing is subjected only to transverse loads exerted by pressurization of the wheel cylinder assembly 40. The backing plates 36 and 38 transmit brake torque directly to the mounting bracket 12. The caliper housing therefore maintains itself in alignment at all times.

The caliper housing shown in FIG. 3 is provided with a circular pipe-like passage 76 through which the notch 52 has been transversely cut and in which the wheel cylinder assembly 40 is mounted. The bridging section is an integral part of the side sections 46 and 48, and it can be seen that all of the transversely aligned cross section areas of the bridging and side sections are formed to a common cross section pattern. For example, the longitudinally-extending passages 78 and 80 formed through the upper portions of the side sections 46 and 48 and through the bridging section 50 have the same cross section pattern throughout. In different caliper housing designs, different cross section pattern arrangements such as those illustrated in FIGS. 8 and 9 may be provided to obtain the desired housing characteristics.

The caliper housing 30 is made from a section of an extruded pipe in the manner diagrammatically illustrated in FIGS. 4, 5 and 6. The pipe 82 is extruded from the extrusion die 84. The pipe is then transversely severed, as illustrated in FIG. 5, to provide a plurality of pipe units 86. Each pipe unit is then notched to provide notch 52, with the notch passing transversely through a portion of the pipe unit. The notch may be formed by broaching operations, Depending upon the particular housing, other notch forms may be utilized than that shown, as Well as other housing ends. In some instances it is preferable to perform the notching operation prior to transversely severing the pipe 82 into the plurality of pipe units 86.

The pipe section shown in FIG. 8 is similar to that utilized for making the caliper housing 30 of FIG. 3. However, in this instance only one passage 88 is provided through the portion of the pipe which ultimately includes the housing bridging section 50. In the construction shown in FIG. 9, passages 90 and 92 are positioned on either side of the passage 94 in the portion of the pipe which eventually becomes the bridging section of the caliper housing. Passages 90 and 92 are illustrated as having slotted outer sides which further decrease weight and the use of material without adversely affecting the strength of the completed caliper housing.

What is claimed is:

1.. The method of manufacturing disc brake caliper housings comprising the steps of:

(a) forming a multiple-passage pipe,

(b) transversely severing the pipe at angles other than a right angle to the axis of the pipe into a plurality of pipe units,

(c) and notching each pipe unit transversely through only one of the multiple pipe passages to provide a caliper housing bridging section by the unnotched part including the other of the multiple pipe passages and caliper housing side sections on either side of the notch, said notching step including forming each pipe unit notch with axially recessed parallel side sections to provide brake pad receiving guide surfaces.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 9/1960 France.

JOHN F. CAMPBELL, Primary Examiner V. A. DI PALMA, Assistant Examiner U.S. Cl. X.R. 

